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The invention relates to compounds and methods for use in biologic systems. More particularly, processes that transfer nucleic acids into cells are provided. Nucleic acids in the form of naked DNA or a nucleic acid combined with another compound are delivered to cells.
Biotechnology includes the delivery of a genetic information to a cell to express an exogenous nucleotide sequence, to inhibit, eliminate, augment, or alter expression of an endogenous nucleotide sequence, or to express a specific physiological characteristic not naturally associated with the cell. Polynucleotides may be coded to express a whole or partial protein, or may be anti-sense.
A basic challenge for biotechnology and thus its subpart, gene therapy, is to develop approaches for delivering genetic information to cells of a patient in a way that is efficient and safe. This problem of xe2x80x9cdrug delivery,xe2x80x9d where the genetic material is a drug, is particularly challenging. If genetic material are appropriately delivered they can potentially enhance a patient""s health and, in some instances, lead to a cure. Therefore, a primary focus of gene therapy is based on strategies for delivering genetic material in the form of nucleic acids. After delivery strategies are developed they may be sold commercially since they are then useful for developing drugs.
Delivery of a nucleic acid means to transfer a nucleic acid from a container outside a mammal to near or within the outer cell membrane of a cell in the mammal. The term transfection is used herein, in general, as a substitute for the term delivery, or, more specifically, the transfer of a nucleic acid from directly outside a cell membrane to within the cell membrane. The transferred (or transfected) nucleic acid may contain an expression cassette. If the nucleic acid is a primary RNA transcript that is processed into messenger RNA, a ribosome translates the messenger RNA to produce a protein within the cytoplasm. If the nucleic acid is a DNA, it enters the nucleus where it is transcribed into a messenger RNA that is transported into the cytoplasm where it is translated into a protein. Therefore if a nucleic acid expresses its cognate protein, then it must have entered a cell. A protein may subsequently be degraded into peptides, which may be presented to the immune system.
It was first observed that the in vivo injection of plasmid DNA into muscle enabled the expression of foreign genes in the muscle (Wolff, J A, Malone, R W, Williams, P, et al. Direct gene transfer into mouse muscle in vivo. Science 1990;247:1465-1468.). Since that report, several other studies have reported the ability for foreign gene expression following the direct injection of DNA into the parenchyma of other tissues. Naked DNA was expressed following its injection into cardiac muscle (Acsadi, G., Jiao, S., Jani, A., Duke, D., Williams, P., Chong, W., Wolff, J. A. Direct gene transfer and expression into rat heart in vivo. The New Biologist 3(1), 71-81, 1991.).
In one preferred embodiment, a process is described for delivering a polynucleotide into a parenchymal cell of a mammal, comprising making a polynucleotide such as a nucleic acid. Then, inserting the polynucleotide into a mammalian vessel, such as a blood vessel and increasing the permeability of the vessel. Finally, delivering the polynucleotide to the parenchymal cell thereby altering endogenous properties of the cell. Increasing the permeability of the vessel consists of increasing pressure against vessel walls. Increasing the pressure consists of increasing a volume of fluid within the vessel. Increasing the volume consists of inserting the polynucleotide in a solution into the vessel wherein the solution contains a compound which complexes with the polynucleotide. A specific volume of the solution is inserted within a specific time period. Increased pressure is controlled by altering the specific volume of the solution in relation to the specific time period of insertion. The vessel may consist of a tail vein. The parenchymal cell is a cell selected from the group consisting of liver cells, spleen cells, heart cells, kidney cells and lung cells.
In another embodiment, a complex for providing nucleic acid expression in a cell is provided, comprising mixing a polynucleotide and a polymer to form the complex wherein the zeta potential of the complex is not positive. Then, delivering the complex to the cell wherein the nucleic acid is expressed.
In another embodiment, a process is described for delivering a polynucleotide complexed with a compound into a parenchymal cell of a mammal, comprising making the polynucleotide-compound complex wherein the compound is selected from the group consisting of amphipathic compounds, polymers and non-viral vectors. Inserting the polynucleotide into a mammalian vessel and increasing the permeability of the vessel. Then, delivering the polynucleotide to the parenchymal cell thereby altering endogenous properties of the cell.
In yet another embodiment, a process is described for transfecting genetic material into a mammalian cell, comprising designing the genetic material for transfection. Inserting the genetic material into a mammalian blood vessel. Increasing permeability of the blood vessel and delivering the genetic material to the parenchymal cell for the purpose of altering endogenous properties of the cell.